1. Field of the Invention
The present invention relates to chip-type electronic components and, in particular, small chip-type electronic components in the shape of an approximately rectangular solid, such as multilayer ceramic capacitors, inductors, resistors and semiconductor elements.
2. Description of Related Art
Recently, attempts to miniaturize electronic equipment and achieve high densification of mounting are being pursued. For example, as described in Japanese Patent Application Laid-Open Publication No. 2003-318312, chip-type electronic components having different characteristics, such as a capacitor, an inductor, a resistor, a semiconductor element, are mounted together on a substrate constituting the electronic equipment. As such a chip-type electronic component described in this publication (corresponding to a circuit element of Japanese Patent Application Laid-Open Publication No. 2003-318312), there is a small multilayer ceramic capacitor (2 mm in length; 1.25 mm in width; and 1.25 mm in thickness), which is for example described in Japanese Patent Application Laid-Open Publication No. 2000-114097.
Since there are a large variety of chips on the substrate as above described, the operations during mounting and repair are complicated. Consequently, there has been a proposal to describe, on the surface of a used chip-type electronic component, information such as its characteristic and its manufacturer's name. However, due to the high densification of the substrate and the miniaturization of the chip-type electronic component, it is difficult to make visible the information on the component surface.
Moreover, the miniaturized chip-type electronic component itself is of low mechanical strength. Therefore, there arises the problem that, when the chip-type electronic component is transported and mounted onto the substrate by an automatic machine, it may be broken depending on the grip strength, and the speed and strength when it is disposed on the substrate. In addition, since the edge portions and the like of the fired ceramic body have angularity, chipping is apt to occur at the time of mounting.
On the other hand, FIG. 14 is a schematic sectional view illustrating a conventional typical multilayer ceramic capacitor, which is described in No. 23, electronic components, C5101-10, JIS handbook 2001, edited by the Japanese Standards Association. As shown in FIG. 14, this multilayer ceramic capacitor has a pair of external electrodes 73 on the opposing end surfaces of a ceramic body 71. In such a multilayer chip-type electronic component, the outermost periphery dimension containing the external electrodes 73 is standardized. Specifically, a thickness t3 in the laminate direction of the ceramic body 71 is smaller than a thickness t4 in the same direction of the external electrodes 73, but the standardized dimension of the multilayer electronic component is specified by the above-mentioned thickness t4 of the external electrodes 73.
In manufacturing the multilayer ceramic capacitor, to achieve miniaturization and high capacity, the overall dimension is designed to be as small as possible by increasing the dimension of the ceramic body 71, which is a capacity generating part, as much as possible, and making the external electrode 73 as thin as possible.
However, if the external electrodes 73 are formed thin, the ceramic body 71 as a capacitor generating part can be made large, but there arises the problem that, during mounting, solder erosion occurs at the external electrodes 73, and stripping of the external electrodes 73 are also apt to occur in the steps of mounting and transportation.
In contrast, when the external electrodes 73 are formed thick for preventing the occurrence of stripping, it is necessary to miniaturize the ceramic body 71, so that electrostatic capacity is suppressed to be low. Further, it is liable to have such a structure that the external electrodes 73 protrude from the external shape surface of the ceramic body 71. Therefore, there arises the problem that, at the time of shock such as drop, the external electrodes 73 are more liable to be an impact surface, so that these are susceptible to breakage.